Berserk (凶暴な, Violent) is a status condition that debuted in Fire Emblem: Genealogy of the Holy War.
When inflicted with this status, the afflicted unit loses control and will automatically attack the weakest unit within their range at the end of their relevant phase, regardless of whether the target is an ally or an enemy of the berserked unit. In the case of player units afflicted by berserk status, the player will not be allowed to move the unit, and they will be moved automatically by the game once the player ends their phase.
If a berserked unit attacks one of their allies, their ally will not be able to attack them back at all, regardless of their weapon; the exception is Thracia 776, where units can fight back against berserked allies. Additionally, berserked units will not gain experience.
Like many negative status conditions, it can be healed with a Restore staff.
In Fire Emblem: The Blazing Blade, in the Final Chapter, after beating the six bosses in each room, the last hall opens, and the Druid inside casts Berserk at long range to affect the party. This can be a great problem and it is recommended to get a Restore staff to counter this.
Although rare, if a boss is afflicted with Berserk status, it will cure itself in the following turn. Using it in this way will produce no benefits.
Berserk infliction methods